MORPHOLOGY AND INFECTIVITY OF CULTIVATED TRYPANOSOMA-AMBYSTOMAE

Cultures of Trypanosoma ambystomae were initiated and maintained in hy po-osmotic biphasic blood-agar medium. Epimastigotes and trypomastigot es occurred in culture and although they were similar in size, epimast igotes predominated with about 70% of all stages. Epimastigotes divide d by equal binary fission and occasionally formed rosettes. Cultured t rypomastigotes did not divide. Cultures isolated 118 days earlier were infective to all 3 laboratory-reared Ambystoma jeffersonianum and to 2 of 3 Ambystoma mexicanum; the latter is a new host record. Trypanoso mes were morphometrically similar in both experimental hosts. Specimen s from 20-day-old experimental infections were smaller than those from natural infections. Dividing bloodstream forms were detected in exper imental infections. Standard culture conditions should be adopted if t he morphology of culture forms is to have taxonomic significance.